@@ -1734,6 +1734,7 @@ static int iproute_list_flush_or_save(int argc, char **argv, int action)
char *od = NULL;
unsigned int mark = 0;
rtnl_filter_t filter_fn;
+ int ret;
if (action == IPROUTE_SAVE) {
if (save_route_prep())
@@ -1939,7 +1940,11 @@ static int iproute_list_flush_or_save(int argc, char **argv, int action)
new_json_obj(json);
- if (rtnl_dump_filter(&rth, filter_fn, stdout) < 0) {
+ ret = rtnl_dump_filter(&rth, filter_fn, stdout);
+
+ /* Let's ignore ENOENT error if we want to dump RT_TABLE_MAIN table */
+ if (ret < 0 &&
+ !(errno == ENOENT && filter.tb == RT_TABLE_MAIN)) {
fprintf(stderr, "Dump terminated\n");
return -2;
}
We started to use in-kernel filtering feature which allows to get only needed tables (see iproute_dump_filter()). From the kernel side it's implemented in net/ipv4/fib_frontend.c (inet_dump_fib), net/ipv6/ip6_fib.c (inet6_dump_fib). The problem here is that behaviour of "ip route save" was changed after c7e6371bc ("ip route: Add protocol, table id and device to dump request"). If filters are used, then kernel returns ENOENT error if requested table is absent, but in newly created net namespace even RT_TABLE_MAIN table doesn't exist. It is really allocated, for instance, after issuing "ip l set lo up". Reproducer is fairly simple: Error: ipv4: FIB table does not exist. Dump terminated Expected result here is to get empty dump file (as it was before this change). This affects on CRIU [1] because we use ip route save in dump process, to workaround problem in tests we just put loopback interface up in each net namespace. Links: [1] https://github.com/checkpoint-restore/criu/issues/747 [2] https://www.spinics.net/lists/netdev/msg559739.html Fixes: c7e6371bc ("ip route: Add protocol, table id and device to dump request") Cc: David Ahern <dsahern@kernel.org> Cc: Stephen Hemminger <stephen@networkplumber.org> Cc: Andrei Vagin <avagin@gmail.com> Cc: Alexander Mikhalitsyn <alexander@mihalicyn.com> Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> --- ip/iproute.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)